System for increasing antimicrobial efficacy in a poultry processing tank

ABSTRACT

Methods and related apparatus for improving the efficacy of antimicrobial agents within processing tanks. Processing tanks can include side streams for introducing antimicrobial agents into the processing tanks. The antimicrobial agents will be added and mixed in the side stream to form a processing solution. Additional actions can be conducted on the processing solution within the side stream including any and or all of heating, pumping, sampling, measuring, testing and pH adjustment of the processing solution. The processing solution is divided into at least two processing solution steams, which can be introduced at two different and distinct locations within the processing tank such as a carcass introduction end and a carcass removal end. By simultaneously introducing at least two processing solution streams at different locations of the processing tank, large concentration gradients of the antimicrobial agent are avoided.

PRIORITY CLAIM

The present continuation application claims priority to U.S. applicationSer. No. 15/676,622 filed Aug. 14, 2017, now U.S. Pat. No. 11,350,640issued Jun. 7, 2022, which claims priority to U.S. ProvisionalApplication No. 62/374,468 filed Aug. 12, 2016 and entitled “METHODS ANDRELATED APPARATUS FOR MEASURING AND ADJUSTING PROCESSING SOLUTION pH FORPOULTRY PROCESSING”, which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present invention is related to processing systems and relatedmethods of operation during poultry processing. More specifically, thepresent invention is directed to methods and related apparatus forincreasing antimicrobial efficacy during poultry processing by reducingconcentration gradients of antimicrobial agents within a processingtank.

BACKGROUND

Commercial poultry processing plants include variety of processing andhandling steps that can allow for the retention, transportation andtransfer of bacteria from carcass to carcass throughout the processingplant. Of particular concern are human pathogenic microorganisms andthose whose metabolism result in rapid spoilage of meat. Thesemicroorganisms, brought into the plant in or on live carcasses, aredisseminated throughout the plant as the post-kill carcasses are handledby processing personnel, touch briefly together during traverse of theshackle lines, or are dipped for periods of time in various aqueoussolutions, like scald baths and chill water.

In response to the presence of bacteria, most processing plants haveimplemented various processes that expose poultry carcasses to desirableantimicrobial chemistries in order to reduce bacterial populations onthe carcasses. While prior chemistries including sodium hypochlorite,trisodium phosphate, various organic acids, ozone, chlorine dioxide andacidified sodium provided benefits, these older technologies sufferedfrom undesirable effects and limitations. Newer antimicrobialchemistries include the use of peroxycarboxylic acids (“PCA”), such asperoxyacetic acid (“PAA”). PAA is a highly efficacious antimicrobialthat was originally used as a hard surface sanitizer, but has morerecently been recognized as possessing superior antimicrobialintervention chemistries for poultry carcasses. PAA provides a broadspectrum of kill of pathogenic and spoilage bacteria while producing noundesirable chemical by-products as the PAA degrades.

PAA, which is also sometimes called peracetic acid, is aperoxycarboxylic acid and is a well known chemical for its strongoxidizing potential, has the molecular formula CH₃COOOH, and has amolecular structure as follows:

An equilibrium PAA solution is produced from an equilibrium mixture ofhydrogen peroxide, acetic acid and water (“equilibrium PAA solution”),which often uses an acid catalyst, e.g., sulfuric acid.

PAA has a pKA of about 8.4, such that about half the PAA is active(free) and about half is dissociated (bound) at a pH of about 8.4. Forexample, a 100 ppm solution of PAA at a pH of about 8.4 has about 50 ppmof active (free) PAA and about 50 ppm of peracetate ion, which is about5 to about 10 times less effective than active PAA.

U.S. Pat. No. 5,632,676, which pertains to the application ofequilibrium PAA solutions to fowl at an application concentration ofabout 100 ppm to about 2000 ppm, discloses such equilibrium solutionshaving a pH around 3.

Hydrogen peroxide is always present in excess in the natural equilibriumformulation of PAA solutions (and other equilibrium PCA solutions). Boththe excess hydrogen peroxide and the PCA produced in the equilibrium PCAsolution (such as PAA) are the sources of the oxidative chemistry thatcan create undesirable organoleptic effects on poultry skin and flesh,such as extremity darkening and skin bleaching. To mitigate thedevelopment of these undesirable effects, processing plants have reducedeither concentrations of equilibrium PAA solutions (and otherequilibrium PCA solutions) or restricted contact times.

U.S. Pat. No. 5,632,676 includes numerous examples of equilibrium PAAsolutions and concludes that the examples show that effective sanitationoccurs within a narrow peracetic acid concentration range. This patentalso discusses bleaching that is apparent in unadjusted or NaOH adjustedPAA solutions compared to a solution adjusted to pH 5 with disodiumphosphate. Published Patent Application No. 2012/0244261 also discussesproviding a solution of PAA-containing water in a reservoir, measuringthe pH in the reservoir, and then pH adjustment before processing with asource of alkali, pH determination in the reservoir during processingwith pH adjustment as necessary during processing with a source ofalkali to increase the weight of the processed poultry product, with thealkali adjusted PAA solutions having a pH between about 6 to about 9 inthe processing reservoir before processing begins and during theprocessing.

Because of the importance of pH in driving the equilibrium equation toproper concentrations of PAA, it would be advantageous to improve uponthe accuracy of pH measurement and consistency within the processingsystems. It would also be advantageous to properly monitor and maintainthe pH of PAA during processing to determine the proper active PAAcompared to peracetate ions in the solution during processing. Stillfurther, due to the amount of organic material in the processing tank,it would be advantageous to have accurate monitoring of the pH of theprocessing solution without having to routinely clean the pH probes thatcan be fouled by the organic material. Finally, it would be advantageousto improve upon existing processing systems so as to reduceconcentration gradients across a processing tank, as well as to increasethe antimicrobial efficacy of intervention processing solutions inprocessing tanks.

SUMMARY

Various aspects of the present invention include both methods andrelated apparatus as well as systems for improving the efficacy ofantimicrobial agents within processing tanks. Typically, methods,apparatus and systems of the present invention will involve the use ofside streams to add appropriate antimicrobial agents into the processingtanks. Within these side streams, the antimicrobial agents will be addedto a source solution and mixed to form a processing solution within theside stream. In some embodiments, the source solution is fresh water,while in some other embodiments the source solution may be a recycled,reclaimed and/or reused processing solution comprising one or moreintervention solution components, such as a peroxycarboxylic acid, PAA,sodium hypochlorite or other processing chemistries. Depending upon theapplication, additional actions can be conducted on the processingsolution within the side stream including any and or all of heating, forexample, with heat exchangers, pumping, sampling, measuring, testingand/or pH adjusting the processing solution.

The invention may generally further comprise the processing solutionhaving at least two distinct streams, for example, a first and secondprocessing solution stream, wherein the at least two distinct streamswill be introduced at two different and distinct locations within theprocessing tank. For instance, the first processing solution stream canbe introduced proximate a carcass introduction location of theprocessing tank, while the second processing solution stream can besimultaneously introduced at a carcass removal location of theprocessing tank. In some embodiments, the first and second processingstreams are provided by separate processing stream sources. Forinstance, the first processing stream may be a source of fresh watermixed with an intervention chemistry, while the second processing streammay be a recycled, reclaimed or reused processing source mixed with anintervention chemistry. In some other embodiments, a single processingsolution is provided that can be divided into the first and secondprocessing streams. In some embodiments, the processing solution can bedivided into additional streams that can be introduced at variouslocations between the carcass introduction location and the carcassremoval location of the processing tank. By simultaneously introducingat least two processing solution streams at different locations of theprocessing tank, large concentration gradients can be avoided with theprocessing tank such that each animal carcass is exposed to sufficientamounts of the antimicrobial agent across a length of the processingtank. Furthermore, reduced amounts of antimicrobial agent can beutilized as there is no longer the necessity to add excessive amounts ofthe antimicrobial agent at an upstream side of the processing tank toensure that adequate levels of the antimicrobial agent are present atthe downstream side. Various aspects of the present invention have beenfound to be especially useful when the processing tank comprises apoultry chiller tank for cooling poultry carcasses.

In another aspect, the present invention improves upon pH control andconsistency within processing systems having an antimicrobial solutionby adding a pH adjusting product and/or peroxycarboxylic acids, such asPAA, to the inlet piping system or to a tank in a side or ancillarysystem, such that the pH adjusting product is thoroughly mixed with theperoxycarboxylic acid prior to its introduction into a processing tanksystem, such as a chiller tank.

In some embodiments, the ancillary system can comprise one or more ofthe various piping of the processing tank system, for example, inletflow piping, makeup flow piping, and tank recirculation piping. In suchaspects, the processing water can have a pH between about 7 and 12 priorto addition of the peroxycarboxylic acid, in other aspects a pH betweenabout 7.5 and 9. Once the peroxycarboxylic acid is added to theprocessing water, the solution is thoroughly mixed before pHdetermination and introduction of the processing solution into theprocessing tank.

In some other embodiments, the ancillary system can comprise one or morestand-alone tanks, for example, a mixing tank or similar reservoir,which supplies the processing solution having the desired pH to theprocessing tank system. Through the mixing of the processing water withthe peroxycarboxylic acid and pH determination in an ancillary system,pH need only be measured once (in the ancillary system) as the velocityof the water in the ancillary system (either piping or stand-alonemixing tank) and the associated high Reynolds number, resulting in theprocessing solution having the desired pH between about 7 and about 12,in some other instances between about 7.5 and 11, and other instancesbetween about 8.0 and 10.0, being thoroughly mixed prior to beingintroduced into the process tank. As all of the water entering the tank(either incoming, rinse, or recirculation) is at the same pH, consistentpH contacts each poultry carcass as the birds travel from a front end toa back end of the processing tank.

In some embodiments, the pH of the processing solution can also bedetermined in the overflow of the processing tank. As all of the waterentering the tank travels from the front end to the back end of theprocessing tank, the overflow at the back end of the processing tankwill provide an accurate pH determination after the carcasses travel theentire distance of the processing tank. In other words, determining thepH of the processing solution after it exits the processing tank willprovide a more accurate determination of the pH than in the tank itselfwhere processing has not been completed or organic material canbuild-up.

The above summary is not intended to describe each illustratedembodiment or every implementation of the subject matter hereof. Thefigures and the detailed description that follow more particularlyexemplify various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Subject matter hereof may be more completely understood in considerationof the following detailed description of various embodiments inconnection with the accompanying figures, in which:

FIG. 1 is a schematic illustration of a poultry carcass dip tankaccording to a representative embodiment of the present invention.

FIG. 2 is a schematic illustration of a poultry carcass water chillertank with red water loop system according to a representative embodimentof the present invention.

FIG. 3 is a schematic illustration of a poultry carcass water chillertank red water loop system according to a representative embodiment ofthe present invention.

FIG. 4 is a schematic illustration of a poultry carcass water chillertank red water loop system according to a representative embodiment ofthe present invention.

FIG. 5A is schematic illustration of a poultry carcass water chillertank according to the prior art.

FIG. 5B is a schematic illustration of a poultry carcass water chillertank according to a representative embodiment of the present invention.

FIG. 6 is a schematic illustration of a poultry carcass water chillertank according to a representative embodiment of the present invention.

While various embodiments are amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail. It should beunderstood, however, that the intention is not to limit the claimedinventions to the particular embodiments described. On the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the subject matter as defined bythe claims.

DETAILED DESCRIPTION OF THE DRAWINGS

Representative embodiments of the present invention provide methods andsystems for improving the efficacy of antimicrobial agents in processingtanks by eliminating large concentration gradients across the length ofthe processing tank. In some embodiments, the invention can includeconsistently exposing poultry carcasses to a process solution having asimilar concentration prior to introduction into a first end of aprocessing tank and upon exiting a second end of a processing tank.While the processing solution of the present invention is discussed inreference to a peroxycarboxylic acid, such as PAA, one of ordinary skillin the art will appreciate that the present invention is applicable toone or more antimicrobial components used in processing poultry.

In some embodiments, the invention can include consistently exposingpoultry carcasses to process solution having similar pH prior tointroduction into a first end of a processing tank and upon exiting asecond end of a processing tank. Representative embodiments of thepresent invention utilize one or more ancillary systems for introducinga processing solution having at least one peroxycarboxylic acid in aprocessing water having a pH of about 7 to about 10 that is thoroughlymixed prior to introduction into the processing tank, such that theprocessing tank will not experience zones having different pH levels. Insome embodiments, the ancillary system can comprise a piping inlet orpiping recirculation loop in which the peroxycarboxylic acid is added toa processing water having a desired pH and thoroughly mixed prior to itsintroduction to the processing tank. In some embodiments, the ancillarysystem can comprise a storage tank or similar style reservoir into whichthe peroxycarboxylic acid is added to the processing water having adesired pH and mixed prior to its introduction to the processing tank.In some aspects, a pH adjustment component may need to be added toeither the processing water or processing solution in the ancillarysystem to obtain the desired pH of the processing solution. Regardlessof the design, the ancillary system will have high velocities andcorresponding high Reynolds numbers such that the processing water,peroxycarboxylic acid, and any pH adjustment product is adequately mixedproviding a processing solution having a desired pH and concentration ofthe peroxycarboxylic acid, such as PAA, prior to introduction into theprocessing tank. The present invention can further include measuring thepH within the ancillary system to accurately determine pH prior tointroduction into the processing tank and without concern for fouling ofa pH probe that is a common occurrence due to organic material fromcarcasses within the processing tank itself.

In a first embodiment as illustrated in FIG. 1 , a poultry processingsystem 100 of the present invention can comprise a process tank 101 suchas, for example, a dip tank including a processing solution 102. Theprocessing solution 102 generally comprises a processing watercontaining a peroxycarboxylic acid, preferably PAA, wherein theprocessing water was provided at a desired pH that is advantageous forprocessing and rinsing poultry carcasses and mixed with theperoxycarboxylic acid prior to being provided in the process tank 101.The process tank 101 generally comprises a first end 104 and a secondend 106, wherein an inflow pipe 108 introduces the processing solution102 into the process tank 101 and an outflow pipe 110 removes theprocessing solution 102 from the process tank 101.

As illustrated in FIG. 1 , the inflow pipe 108 can comprise an ancillarywater inflow portion 112, and one or more ancillary systems 114 a and114 b can be used to supply a pH adjustment product and interventionchemistry, such as peroxycarboxylic acid, preferably PAA, to the inflowpipe 108 prior to the processing solution being introduced into theprocess tank 101. For example, the inflow pipe 108 can comprise a watersupply 112 into which the pH adjustment product is directly added byancillary system 114 a, to the extent necessary, to provide a processingwater. The processing water having the desired pH can then have theintervention chemistry, such as peroxycarboxylic acid, preferably PAA,added by ancillary system 114 b. For example, the pH of the water inflowsupply 112 can be measured such that the pH adjustment product can beadded to the water supply 112 through the use of a conventional meteringpump or through a venturi injector or the like to obtain the desired pHof the processing water, preferably between about 7 and about 10.Generally, the flow of the water supply 112 with respect to ancillarysystem 114 a should have a high enough velocity and correspondingly,Reynolds number to thoroughly mix the pH adjustment product into thewater supply 112 to provide a processing water 112 a having the desiredpH before it is introduced into the inflow pipe 108. The pH of thesupply water 112 and/or the processing water 112 a can be determined inthe inflow pipe 108 prior to the introduction of any interventionchemistry, such as peroxycarboxylic acid. Similarly, the flow of theprocessing water 112 a having the desired pH with respect to ancillarysystem 114 b should have a high enough velocity and correspondingly,Reynolds number to thoroughly mix the intervention chemistry, such asperoxycarboxylic acid, preferably PAA, into the processing water 112 ato provide a processing solution 112 b before it is introduced into theinflow pipe 108. The pH of the processing solution 112 b can be measuredin the inflow pipe 108 prior to the introduction of the processingsolution 112 b into the processing tank 101 to confirm the desired pH ofthe processing solution 112 b. Alternatively, the pH of the processingwater 112 a and the processing solution 112 b can both be measured inthe inflow pipe 108.

Alternatively, ancillary system 114 a can comprise a mixing tank orsimilar reservoir into which the pH adjustment product is added to awater supply and thoroughly mixed before being introduced into theinflow pipe 108. Similarly, ancillary system 114 b can comprise a tankor similar reservoir of the intervention chemistry. In this way, the pHof the processing water 112 a is precisely controlled and maintained asthe inflow pipe 108 delivers the processing solution 112 b into thefirst end 104 of the process tank 100. Since the processing solution 112b contains the processing water 112 a at a desired pH thoroughly mixedwith the intervention chemistry, the pH of the processing solution 112 bwill be consistent prior to introduction into the processing tank 101.As such, pH will remain consistent throughout the process tank 101 andthere will not be localized areas of higher or lower pH within theprocess tank 101 as a result of mixing the components within the processtank 101 that would limit the effectiveness of the processing solutionin rinsing, chilling or otherwise treating the poultry carcasses.Furthermore, pH can be monitored in either the inflow pipe 108 or theancillary systems 112 a, 112 b such that a pH probe/sensor is notexposed to potential fouling within the process tank 101.

With reference to FIGS. 2, 3 and 4 , various embodiments of a chillertank with red water loop processing system 200 are illustrated. As willbe described, the water chiller tank with red water loop processingsystem 200 can comprise varying levels of complexity based upon specificprocessing conditions, and as such, a variety of methods and systemdesigns can be implemented to control pH within the water chiller tankwith red water loop processing system.

In all of the illustrated embodiments, the chiller tank with red waterloop processing system 200 comprises chiller tank 202, a heat exchanger204 and an optional tempering box 206. In each of the embodiments, amake-up water stream 208 is supplied to a first end 210 of the chillertank 202 while an overflow stream 212 is removed at a second end 214 ofthe chiller tank 202. In order to maintain temperature of a pH adjustedprocessing solution 216 within the chiller tank 202, a red waterrecirculation loop 218 supplies pH adjusted processing solution 216 fromthe chiller tank 202 to the heat exchanger 204, wherein the temperatureof the pH adjusted processing solution is modified to the desiredtemperature and subsequently returned to the chiller tank 202.

With reference to FIG. 2 , one or more ancillary systems 220 a, 220 bcan supply the intervention chemistry and pH adjustment product and intothe recirculation loop 218, wherein the processing solution 216 isthoroughly mixed and at the desired pH and temperature prior tointroduction into the chiller tank 202. For example, ancillary system220 b can comprise a processing water supply having a pH adjustmentproduct or the pH adjustment product that is directly added to therecirculated processing solution 216 in the red water recirculation loop218. For example, the pH adjustment product can be added to therecirculated processing water through the use of a conventional meteringpump or through a venturi injector or the like. Generally, the flow ofthe recirculated processing water in ancillary red water recirculationloop 218 should have a high enough velocity and correspondingly,Reynolds number to thoroughly mix the pH adjustment product into therecirculated processing water before it is introduced into the heatexchanger and chiller tank 202. Alternatively, ancillary system 220 bcan comprise a mixing tank or similar reservoir into which the pHadjustment product is added and thoroughly mixed with a water supply toprovide a processing water supply 220 b before being introduced into thered water recirculation loop 218. In this way, the pH is preciselycontrolled and maintained as the red water recirculation loop 218delivers the pH adjusted processing solution 216 into the chiller tank202. Similarly, the flow of the recirculated processing water 222 bhaving the desired pH with respect to ancillary system 220 b should havea high enough velocity and correspondingly, Reynolds number tothoroughly mix the intervention chemistry, such as peroxycarboxylicacid, preferably PAA, into the recirculated processing water 222 b toprovide a refreshed processing solution 222 a having a desiredconcentration before it is introduced back into the chiller tank 202.The pH of the processing solution 222 b can be measured in the inflowpipe 218 prior to the introduction of the processing solution 222 a intothe chiller tank 202 to confirm the desired pH of the processingsolution 222 a. Alternatively, the pH of the recirculated processingwater 222 b and the processing solution 222 b can both be measured inthe inflow pipe 218.

In a variation to the embodiment shown in FIG. 2 , the chiller tank withred water loop processing system 200 of FIG. 3 can comprise additionalancillary systems 220 c, 220 d that supply the intervention chemistryand pH adjustment product, respectively, into the make-up water stream208, such that the processing solution 216 is added at the first end 210of the chiller tank 202 in a manner similar to that as previouslydescribed with respect to the processing solution 112 b of the poultryprocessing system 100. In this manner, the processing solution 208 chaving the desired pH and intervention chemistry concentration is addedto the chiller tank 202 at the first end 210 to provide a processingsolution 216 within the chiller tank 202.

Finally in the embodiment illustrated in FIG. 4 , the chiller tank withred water loop processing system 200 can further comprise a bypass loop230 that introduces additional residence time and consequently, mixingof the pH adjustment product before it is introduced into the chillertank 202. As illustrated, the bypass loop 230 can fluidly interconnectthe make-up water stream 208 with the recirculation loop 218. In thisway, one or more ancillary systems 220 a, 220 b, 220 c, 220 d can beutilized to introduce the intervention chemistry (220 a, 220 c) and pHadjustment product (220 b, 220 d) at an advantageous location prior toits introduction into the chiller tank 202. For example, ancillarysystems 220 d can be utilized to supply the pH adjustment productdirectly into the water within the bypass loop 230, while ancillarysystem 220 b can supply the pH adjustment product into the recirculationloop 218 at a point upstream of the connection to the bypass loop 230.In an embodiment, ancillary system 22 c can add intervention chemistryto the processing water 222 d to provide a processing solution 222 cbefore being introduced into the recirculation loop 218. In yet anotheralternative embodiment, ancillary system 220 a can add all or additionalintervention chemistry to the recirculation loop 218 at a pointdownstream of the connection to the bypass loop 230 containingprocessing solution 222 c and recirculated processing solution 222B. Thelocation of the ancillary systems in the chiller chiller tank processingsystem 200 can be advantageously selected to make use of high velocitiesand Reynolds numbers to thoroughly mix the pH adjustment product and/orintervention chemistries prior to its introduction and/or reintroductioninto the chiller tank 202.

In all of the variations of the chiller tank with red water loopprocessing system 200 described herein, a pH sensor/probe can bepositioned in locations remote from the chiller tank 202. For example,the make-up water stream 208, the recirculation loop 218 and/or thebypass loop 230 can contain pH sensor/probes that are not exposed tofouling and/or contamination that can result from exposure to poultrycontaminants within the chiller tank 202. Further, the pH sensor/probescan be located after the pH adjustment product is added to provide theprocessing water and/or after the intervention chemistry to provide theprocessing solution. In this way of the pH sensor/probes maintainedoutside of the chiller tank, maintenance is eliminated or otherwisereduced and operators can have a higher level of confidence that pH ofthe processing solution and concentration of intervention chemistry isat the desired levels before being introduced into the chiller tank 202.

In each of the embodiments shown in FIGS. 1-4 , the overflow 110, 212can also have pH probe/sensors to precisely determine the pH of theprocessing solution 102, 216 after it exits the respective tank. Bydetermining the pH of the processing solution after it exits the tank,the amount of active PAA can be determined as a result of the organicmaterial in the tank, which may determine the pH level and amount ofintervention chemistry in the inlet prior to being introduced into thetank.

In some aspects, the processing solution in the inlet or red waterrecirculation loop prior to introduction into the tank has a pH above7.0 and below 10, in other aspects between about 7.5 and about 9.5 andin other aspects between about 7.2 and 8.6.

In certain aspects, the processing solution has a concentration ofperoxycarboxylic acid from about 1 ppm to about 5000 ppm, preferablyfrom about 5 ppm to about 1000 ppm, preferably from about 10 ppm toabout 200 ppm, and more preferably from about 15 ppm to about 100 ppm.In some aspects, the concentration of active peroxycarboxylic acid inthe processing solution is from about 1 ppm to about 5000 ppm,preferably from about 5 ppm to about 1000 ppm, preferably from about 10ppm to about 200 ppm, and more preferably from about 15 ppm to about 100ppm. In some other aspects, the concentration of active peroxycarboxylicacid and active peroxycarboxylic acid ion in the processing solution isfrom about 1 ppm to about 5000 ppm, preferably from about 5 ppm to about1000 ppm, preferably from about 10 ppm to about 200 ppm, and morepreferably from about 15 ppm to about 100 ppm. In some aspects, theconcentration of the PAA in the processing solution is between about 15ppm and about 100 ppm, preferably between about 15 ppm and about 75 ppm,and in some other aspects between about 20 ppm and 50 ppm.

In certain aspects, the poultry tank design of the present inventionhaving at least a first and a second processing stream is capable ofmaintaining less than about a 10 ppm concentration gradient across theprocessing length of a processing tank, in some aspects less than aboutan 8 ppm concentration gradient, less than about 6 ppm concentrationgradient, less than about 5 ppm concentration gradient, less than about4 ppm concentration gradient, and in other aspects less than about a 3ppm concentration gradient across the processing length of theprocessing tank. In certain aspects, the concentration gradient acrossthe processing length of the processing tank of the present invention isbetween about 1 ppm and about 10 ppm, between about 2 ppm and 8 ppm, andin some other aspects between about 3 ppm and 5 ppm.

Testing

In order to evaluate the efficacy of the present invention, a test wasconducted to compare the performance of a conventional poultry chillertank as represented by FIG. 5A and an improved poultry chiller tankutilizing a side stream to introduce an antimicrobial agent asrepresented by FIG. 5B. In each case, an antimicrobial agent comprisingPAA was introduced into a poultry chiller tank 300 with a target PAAconcentration of 30 ppm in the poultry chiller tank 300. Poultry chillertank 300 comprised a 65 foot long tank with a volume of 40,000 gallons.Poultry chiller tank 300 had a poultry carcass load of greater than34,000 and the carcass processing rate was the same for both tests.

With the conventional poultry chiller tank as represented by FIG. 5A, aconcentrated antimicrobial solution 302 was added at a carcassintroduction end 304 of the poultry chiller tank 300. In the presentcase, antimicrobial solution 302 comprised a solution of water and PAA.During a production shift, samples of a chiller tank solution 306 weretaken at the carcass introduction end 304, a carcass removal end 308 anda chiller tank midpoint 310. The time weighted average of 5 samples ateach location were:

Carcass Introduction End: 35 ppm Chiller Tank Midpoint: 26 ppm CarcassRemoval End: 15 ppm

As can be seen in the sample measurements, a significant length ofpoultry chiller tank 300 experienced concentrations of PAA significantlybelow the desired level of 30 ppm. More specifically, poultry carcassesnear that carcass removal end 308 were exposed to chiller tank solutionhaving half of the desired concentration of PAA. The carcassintroduction end 304 experienced a slightly higher level of PAA due tothe injection of the concentrated antimicrobial solution 302 as well asPAA carryover on poultry carcasses from the prior processing step.

With the poultry chiller tank design of the present invention as show inFIG. 5B, a PAA solution 320 is introduced and mixed into a side stream322 to form a processing solution 324 having a PAA concentration of 30ppm. Processing solution 324 comprised a first processing solution 326that was introduced into the chiller tank 300 at the carcassintroduction end 304 while a second processing solution 328 wasintroduced into the chiller tank 300 at the carcass removal end 308.During a production shift, samples of the chiller tank solution 306 weretaken at the carcass introduction end 304, the carcass removal end 308and the chiller tank midpoint 310. The time weighted average of 5samples at each location were:

Carcass Introduction End: 32 ppm Chiller Tank Midpoint: 28 ppm CarcassRemoval End: 27 ppm

As can be seen in the sample measurements, the poultry chiller tankdesign of the present invention had a much lower concentration gradientacross the length of the poultry chiller tank 300 with the chiller tanksolution 306 at the chiller tank midpoint 310 and carcass removal end308 being much closer to the desired concentration level of 30 ppm. Asmeasured, the poultry chiller tank design of the present invention iscapable of maintaining plus or minus 3 ppm of PAA within the chillertank solution 306 across the length of the poultry chiller tank 300.

While the design illustrated in 5B utilized introduction of only a firstprocessing solution 326 and a second processing solution 328, processingsolution 324 can be further divided into additional processing solutionstreams that can be introduced at additional locations within thepoultry chiller tank 300. For example, processing solution 324 could befurther divided into a third processing solution also having a PAAconcentration of 30 ppm and said third processing solution could beintroduced, for example, at the chiller tank midpoint 310.

Another representative embodiment of a poultry chiller tank 400 isillustrated generally in FIG. 6 . In a manner similar to the previouslydescribed embodiments, poultry chiller tank 400 can include arecirculation line 402 for introducing a PAA solution 404 to one or morelocations of the poultry chiller tank 400 between a carcass introductionend 406 and a carcass removal end 408. In addition to recirculating atank solution 410 from the poultry chiller tank 400, a downstreamprocessing stream 412 can be used to supply make-up water through therecirculation line 402. Downstream processing stream 412 can comprise anaqueous solution that can include an anti-microbial component, such asPAA, from a downstream operation 413, for example, a de-boning stationor final rinse/bath prior to packaging, wherein the organic load isreduced as compared to the upstream poultry chiller tank 400.Recirculation line 402 can comprise a recirculation pH adjustment stream414 as well as a recirculation PAA adjustment stream 416 such that thePAA solution 404 has a desired PAA concentration, for example, between15 ppm and about 100 ppm, preferably between about 15 ppm and about 75ppm, and in some other aspects between about 20 ppm and 50 ppm. Inaddition, poultry chiller tank 400 can comprise another source of PAAsolution, for example, a fresh PAA solution 420. Fresh PAA solution 420can comprise a tank or piping system where a source of fresh orotherwise filtered water 422 is adjusted with a fresh PAA adjustmentstream 424 and/or a fresh pH adjustment stream 426 such that the freshPAA solution 420 has a desired PAA concentration that is substantiallyequivalent to PAA solution 404. Through the introduction of both PAAsolution 404 and fresh PAA solution 420 having equivalent PAAconcentrations, the PAA concentration gradient within the poultrychiller tank 400 can be reduced.

In some aspects, the pH adjustment product is an alkalizing agentapproved for direct food contact. In some aspects, the alkalizing agentis chosen from alkali metals and alkali earth metals, including sodiumhydroxide and/or potassium hydroxide and/or the sodium and/or potassiumsalts of carbonic acid and/or phosphoric acid and/or silicic acid and/orother alkaline chemistries.

Various embodiments of systems, devices, and methods have been describedherein. These embodiments are given only by way of example and are notintended to limit the scope of the claimed inventions. It should beappreciated, moreover, that the various features of the embodiments thathave been described may be combined in various ways to produce numerousadditional embodiments. Moreover, while various materials, dimensions,shapes, configurations and locations, etc. have been described for usewith disclosed embodiments, others besides those disclosed may beutilized without exceeding the scope of the claimed inventions.

The invention claimed is:
 1. An ancillary system in fluid communicationwith a poultry processing tank, the ancillary system comprising: amixing assembly in fluid communication with a source of a processingwater, a reservoir of a pH adjustment product, and a reservoir of asolution of one or more peroxycarboxylic acids, wherein the mixingassembly is configured to mix an inlet stream of the processing water,an inlet stream of the pH adjustment product, and an inlet stream of thesolution of one or more peroxycarboxylic acids to provide a premixed pHadjusted processing solution having a desired pH between about 7 andabout 10 and a desired concentration between about 1 ppm and about 2000ppm; a piping assembly in fluid communication with the mixing assemblyand the poultry processing tank; and an optional pH probe proximatelylocated the mixing assembly for measuring a pH of the premixed pHadjusted processing solution; wherein the mixing assembly is proximatelylocated outside of the poultry processing tank; wherein the pipingassembly is configured to introduce the premixed pH adjusted processingsolution having the desired pH between about 7 and about 10 and thedesired concentration between about 1 ppm and about 2000 ppm from themixing assembly into the poultry processing tank; and wherein thepremixed pH adjusted processing solution introduced into the poultrychiller tank is capable of maintaining a poultry processing solutionwithin the poultry processing tank at the desired pH between about 7 andabout 10 and the desired concentration between about 1 ppm and about2000 ppm during processing at least a portion of one or more poultrycarcasses.
 2. The ancillary system of claim 1, wherein the mixingassembly comprises a mixing tank.
 3. The ancillary system of claim 1,wherein the piping assembly provides fluid communication between themixing assembly and an inflow pipe of the poultry processing tank. 4.The ancillary system of claim 1, wherein the solution of one or moreperoxycarboxylic acids comprises peroxyacetic acid (PAA).
 5. Theancillary system of claim 4, wherein the desired concentration of PAA isbetween about 10 ppm and about 1000 ppm.
 6. The ancillary system ofclaim 4, wherein the desired concentration of PAA is between about 15ppm and about 200 ppm.
 7. The ancillary system of claim 4, wherein thedesired concentration of PAA is between about 15 ppm and about 100 ppm.8. The ancillary system of claim 1, wherein the pH adjustment product isan alkalizing agent chosen from an alkali metal and an alkali earthmetal.
 9. The ancillary system of claim 1, wherein the pH adjustmentproduct is chosen from sodium hydroxide, potassium hydroxide, sodiumsalt of carbonic acid, potassium salt of carbonic acid, phosphoric acid,and silicic acid.
 10. The ancillary system of claim 1, wherein thesolution of one or more peroxycarboxylic acids comprises PAA and the pHadjustment product comprises sodium hydroxide and/or potassiumhydroxide.
 11. The ancillary system of claim 10, wherein the desiredconcentration of PAA is between about 10 ppm and about 1000 ppm.
 12. Theancillary system of claim 10, wherein the desired concentration of PAAis between about 15 ppm and about 200 ppm.
 13. The ancillary system ofclaim 10, wherein the desired concentration of the PAA is between about15 ppm and about 100 ppm.
 14. The ancillary system of claim 1, whereinthe solution of one or more peroxycarboxylic acids comprises PAA, thedesired concentration of the PAA is between about 10 ppm and about 1000ppm, the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof, and the desired pH is between about7.5 and about 9.5.
 15. The ancillary system of claim 14, wherein thedesired concentration of the PAA is between about 15 ppm and about 200ppm, and the desired pH is between about 7.2 and about 8.6.
 16. Theancillary system of claim 1, wherein the premixed pH adjusted processingsolution is capable of being continuously introduced from the mixingassembly to the poultry processing tank during processing of the one ormore poultry carcasses.
 17. The ancillary system of claim 1, wherein thepoultry processing tank is a chiller tank.
 18. The ancillary system ofclaim 1, wherein the poultry processing tank is a dip tank.
 19. Theancillary system of claim 1, wherein the mixing assembly comprises afirst mixing tank in fluid communication with a second mixing tank,wherein the first mixing tank is configured to mix an inlet stream ofthe processing water and an inlet stream of the pH adjustment product toprovide a pH adjusted processing water, and wherein the second mixingtank is configured to mix an inlet stream of the pH adjusted processingwater and an inlet stream of the solution of one or moreperoxycarboxylic acids to provide a premixed pH adjusted processingsolution having the desired pH between about 7 and about 10 and thedesired concentration between about 1 ppm and about 2000 ppm.
 20. Theancillary system of claim 19, wherein the solution of one or moreperoxycarboxylic acids comprises PAA, wherein the pH adjustment productcomprises sodium hydroxide, potassium hydroxide, or a combinationthereof, and wherein the desired concentration of the PAA premixed pHadjusted processing solution is between about 10 ppm and about 1000 ppmand the desired pH is between about 7.5 and about 9.5.
 21. An ancillarysystem in fluid communication with a poultry processing tank, theancillary system comprising: a mixing assembly configured to be in fluidcommunication with a source of a processing water, a reservoir of a pHadjustment product, and a reservoir of a solution of one or moreperoxycarboxylic acids, wherein the mixing assembly is configured to mixan inlet stream of the processing water, an inlet stream of the pHadjustment product, and an inlet stream of the solution of one or moreperoxycarboxylic acids to provide a premixed pH adjusted processingsolution having a desired pH between 7 and 10 and a desiredconcentration between 1 ppm and 2000 ppm; wherein the mixing assembly isproximately located outside of the poultry processing tank; wherein themixing assembly is configured to be in fluid communication with thepoultry processing tank to introduce the premixed pH adjusted processingsolution having the desired pH between 7 and 10 and the desiredconcentration between 1 ppm and 2000 ppm from the mixing assembly intothe poultry processing tank; and wherein the premixed pH adjustedprocessing solution configured to be introduced into the poultry chillertank is capable of maintaining a poultry processing solution within thepoultry processing tank at the desired pH between 7 and 10 and thedesired concentration between 1 ppm and 2000 ppm during processing atleast a portion of one or more poultry carcasses.
 22. The ancillarysystem of claim 21, wherein the mixing assembly comprises a mixing tank.23. The ancillary system of claim 22, further comprising a pipingassembly providing fluid communication between the mixing tank and aninflow pipe of the poultry processing tank.
 24. The ancillary system ofclaim 21, further comprising a piping assembly providing fluidcommunication between the mixing assembly and an inflow pipe of thepoultry processing tank.
 25. The ancillary system of claim 21, whereinthe solution of one or more peroxycarboxylic acids comprisesperoxyacetic acid (PAA).
 26. The ancillary system of claim 25, whereinthe desired concentration of PAA is between 10 ppm and 1000 ppm.
 27. Theancillary system of claim 26, wherein the pH adjustment productcomprises sodium hydroxide, potassium hydroxide, or a combinationthereof, and the desired pH is between 7.5 and 9.5.
 28. The ancillarysystem of claim 25, wherein the desired concentration of PAA is between15 ppm and 200 ppm.
 29. The ancillary system of claim 28, wherein the pHadjustment product comprises sodium hydroxide, potassium hydroxide, or acombination thereof, and the desired pH is between 7.5 and 9.5.
 30. Theancillary system of claim 25, wherein the desired concentration of PAAis between 15 ppm and 100 ppm.
 31. The ancillary system of claim 30,wherein the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof, and the desired pH is between 7.5and 9.5.
 32. The ancillary system of claim 21, wherein the pH adjustmentproduct is an alkalizing agent chosen from an alkali metal and an alkaliearth metal.
 33. The ancillary system of claim 21, wherein the pHadjustment product is chosen from sodium hydroxide, potassium hydroxide,sodium salt of carbonic acid, potassium salt of carbonic acid,phosphoric acid, and silicic acid.
 34. The ancillary system of claim 21,wherein the solution of one or more peroxycarboxylic acids comprisesPAA, and the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof.
 35. The ancillary system of claim34, wherein the desired concentration of PAA is between 10 ppm and 1000ppm.
 36. The ancillary system of claim 34, wherein the desiredconcentration of PAA is between 15 ppm and 200 ppm.
 37. The ancillarysystem of claim 34, wherein the desired concentration of the PAA isbetween 15 ppm and 100 ppm.
 38. The ancillary system of claim 21,wherein the solution of one or more peroxycarboxylic acids comprisesPAA, the desired concentration of the PAA is between 10 ppm and 1000ppm, the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof, and the desired pH is between 7.2and 9.5.
 39. The ancillary system of claim 38, wherein the desiredconcentration of the PAA is between 15 ppm and 200 ppm, and the desiredpH is between 7.2 and 8.6.
 40. The ancillary system of claim 21, whereinthe premixed pH adjusted processing solution is capable of beingcontinuously introduced from the mixing assembly to the poultryprocessing tank.
 41. The ancillary system of claim 21, wherein themixing assembly comprises a first mixing tank in fluid communicationwith a second mixing tank, wherein the first mixing tank is configuredto mix an inlet stream of the processing water and an inlet stream ofthe pH adjustment product to provide a pH adjusted processing water, andwherein the second mixing tank is configured to mix an inlet stream ofthe pH adjusted processing water and an inlet stream of the solution ofone or more peroxycarboxylic acids to provide the premixed pH adjustedprocessing solution having the desired pH between 7 and 10 and thedesired concentration between 1 ppm and 2000 ppm.
 42. The ancillarysystem of claim 21, wherein the solution of one or more peroxycarboxylicacids comprises PAA, wherein the pH adjustment product comprises sodiumhydroxide, potassium hydroxide, or a combination thereof, and whereinthe desired concentration of the PAA premixed pH adjusted processingsolution is between 10 ppm and 200 ppm and the desired pH is between 7.5and 9.5.
 43. The ancillary system of claim 42, wherein the poultryprocessing tank is a chiller tank.
 44. The ancillary system of claim 43,further comprising a pH probe proximately located the mixing assemblyfor measuring a pH of the premixed pH adjusted processing solution. 45.The ancillary system of claim 43, further comprising a pH probeproximately located an inflow pipe to the chiller tank for measuring apH of the premixed pH adjusted processing solution.
 46. The ancillarysystem of claim 43, further comprising a pH probe proximately locatedoutside the chiller tank for measuring a pH of the premixed pH adjustedprocessing solution.
 47. The ancillary system of claim 43, wherein themixing assembly comprises a metering pump.
 48. The ancillary system ofclaim 43, wherein the mixing assembly comprises a venturi injector. 49.The ancillary system of claim 43, further comprising a piping assemblyproviding fluid communication between the mixing assembly and thechiller tank.
 50. The ancillary system of claim 42, wherein the poultryprocessing tank is a dip tank.
 51. The ancillary system of claim 50,further comprising a pH probe proximately located an inflow pipe to thedip tank for measuring a pH of the premixed pH adjusted processingsolution.
 52. The ancillary system of claim 50, wherein the mixingassembly comprises a metering pump.
 53. The ancillary system of claim50, wherein the mixing assembly comprises a venturi injector.
 54. Theancillary system of claim 50, further comprising a piping assemblyproviding fluid communication between the mixing assembly and the diptank.
 55. The ancillary system of claim 21, wherein the source of theprocessing water comprises fresh water, recycled water, reclaimed wateror reused processing solution comprising water.
 56. The ancillary systemof claim 21, wherein the premixed pH adjusted processing solution isintroduced into the poultry processing tank and maintains the poultryprocessing solution within the poultry chiller tank at the desired pHbetween 7 and 10 and the desired concentration between 1 ppm and 2000ppm during processing at least a portion of the one or more poultrycarcasses.
 57. The ancillary system of claim 21, wherein the premixed pHadjusted processing is introduced into the poultry processing tank andeliminates an undesirable concentration gradient across the length ofthe poultry processing tank during processing at least a portion of theone or more poultry carcasses.
 58. The ancillary system of claim 21,wherein the premixed pH adjusted processing solution is introduced intothe poultry processing tank and maintains a concentration gradientacross a processing length of the poultry processing tank that is lessthan about 10 ppm during processing at least a portion of the one ormore poultry carcasses.
 59. The ancillary system of claim 21, whereinthe premixed pH adjusted processing solution is continuously introducedinto the poultry processing tank during processing at least a portion ofthe one or more poultry carcasses.
 60. The ancillary system of claim 59,wherein the solution of one or more peroxycarboxylic acids comprisesperoxyacetic acid (PAA).
 61. The ancillary system of claim 60, whereinthe desired concentration of PAA is between 10 ppm and 1000 ppm.
 62. Theancillary system of claim 61, wherein the pH adjustment productcomprises sodium hydroxide, potassium hydroxide, or a combinationthereof, and the desired pH is between 7.5 and 9.5.
 63. The ancillarysystem of claim 60, wherein the desired concentration of PAA is between15 ppm and 200 ppm.
 64. The ancillary system of claim 63, wherein the pHadjustment product comprises sodium hydroxide, potassium hydroxide, or acombination thereof, and the desired pH is between 7.5 and 9.5.
 65. Theancillary system of claim 60, wherein the desired concentration of PAAis between 15 ppm and 100 ppm.
 66. The ancillary system of claim 65,wherein the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof, and the desired pH is between 7.5and 9.5.
 67. The ancillary system of claim 60, wherein the pH adjustmentproduct is an alkalizing agent chosen from an alkali metal and an alkaliearth metal.
 68. The ancillary system of claim 60, wherein the pHadjustment product is chosen from sodium hydroxide, potassium hydroxide,sodium salt of carbonic acid, potassium salt of carbonic acid,phosphoric acid, and silicic acid.
 69. The ancillary system of claim 60,wherein the solution of one or more peroxycarboxylic acids comprisesPAA, and the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof.
 70. The ancillary system of claim69, wherein the desired concentration of PAA is between 10 ppm and 1000ppm.
 71. The ancillary system of claim 69, wherein the desiredconcentration of PAA is between 15 ppm and 200 ppm.
 72. The ancillarysystem of claim 69, wherein the desired concentration of the PAA isbetween 15 ppm and 100 ppm.
 73. The ancillary system of claim 60,wherein the solution of one or more peroxycarboxylic acids comprisesPAA, the desired concentration of the PAA is between 10 ppm and 1000ppm, the pH adjustment product comprises sodium hydroxide, potassiumhydroxide, or a combination thereof, and the desired pH is between 7.2and 9.5.
 74. The ancillary system of claim 73, wherein the desiredconcentration of the PAA is between 15 ppm and 200 ppm, and the desiredpH is between 7.2 and 8.6.
 75. The ancillary system of claim 60, whereinthe mixing assembly comprises a first mixing tank in fluid communicationwith a second mixing tank, wherein the first mixing tank is configuredto mix an inlet stream of the processing water and an inlet stream ofthe pH adjustment product to provide a pH adjusted processing water, andwherein the second mixing tank is configured to mix an inlet stream ofthe pH adjusted processing water and an inlet stream of the solution ofone or more peroxycarboxylic acids to provide a premixed pH adjustedprocessing solution having the desired pH between 7 and 10 and thedesired concentration between 1 ppm and 2000 ppm.
 76. The ancillarysystem of claim 60, wherein the solution of one or more peroxycarboxylicacids comprises PAA, wherein the pH adjustment product comprises sodiumhydroxide, potassium hydroxide, or a combination thereof, and whereinthe desired concentration of the PAA premixed pH adjusted processingsolution is between 10 ppm and 200 ppm and the desired pH is between 7.5and 9.5.
 77. The ancillary system of claim 21, wherein the premixed pHadjusted processing is introduced into the poultry processing tank toexpose at least a portion of the one or more poultry carcasses to thepoultry processing solution maintained at the desired pH between 7.2 and9.5 and the desired concentration between 15 ppm and 200 ppm.
 78. Theancillary system of claim 21, wherein the premixed pH adjustedprocessing solution is introduced into the poultry processing tank andmaintains the poultry processing solution within the poultry chillertank at the desired pH between 7.2 and 9.5 and the desired concentrationbetween 15 ppm and 200 ppm during processing at least a portion of theone or more poultry carcasses.
 79. The ancillary system of claim 78,wherein the poultry processing solution within the poultry chiller tankcomprises a concentration of active peroxycarboxylic acid and aconcentration of active peroxycarboxylic acid ion between 15 ppm and2000 ppm.